Internet Engineering Task Force (IETF) M. Bagnulo
Request for Comments: 7398 UC3M
Category: Informational T. Burbridge
ISSN: 2070-1721 BT
S. Crawford
SamKnows
P. Eardley
BT
A. Morton
AT&T Labs
February 2015
Internet Engineering Task Force (IETF) M. Bagnulo
Request for Comments: 7398 UC3M
Category: Informational T. Burbridge
ISSN: 2070-1721 BT
S. Crawford
SamKnows
P. Eardley
BT
A. Morton
AT&T Labs
February 2015
A Reference Path and Measurement Points for Large-Scale Measurement of Broadband Performance
宽带性能大规模测量的参考路径和测量点
Abstract
摘要
This document defines a reference path for Large-scale Measurement of Broadband Access Performance (LMAP) and measurement points for commonly used performance metrics. Other similar measurement projects may also be able to use the extensions described here for measurement point location. The purpose is to create an efficient way to describe the location of the measurement point(s) used to conduct a particular measurement.
本文档定义了宽带接入性能（LMAP）大规模测量的参考路径和常用性能指标的测量点。其他类似的测量项目也可以使用此处描述的扩展来定位测量点。目的是创建一种有效的方法来描述用于进行特定测量的测量点的位置。
Status of This Memo
关于下段备忘
This document is not an Internet Standards Track specification; it is published for informational purposes.
本文件不是互联网标准跟踪规范；它是为了提供信息而发布的。
This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Not all documents approved by the IESG are a candidate for any level of Internet Standard; see Section 2 of RFC 5741.
本文件是互联网工程任务组（IETF）的产品。它代表了IETF社区的共识。它已经接受了公众审查，并已被互联网工程指导小组（IESG）批准出版。并非IESG批准的所有文件都适用于任何级别的互联网标准；见RFC 5741第2节。
Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc7398.
有关本文件当前状态、任何勘误表以及如何提供反馈的信息，请访问http://www.rfc-editor.org/info/rfc7398.
Copyright Notice
版权公告
Copyright (c) 2015 IETF Trust and the persons identified as the document authors. All rights reserved.
版权所有（c）2015 IETF信托基金和确定为文件作者的人员。版权所有。
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.
本文件受BCP 78和IETF信托有关IETF文件的法律规定的约束(http://trustee.ietf.org/license-info)自本文件出版之日起生效。请仔细阅读这些文件，因为它们描述了您对本文件的权利和限制。从本文件中提取的代码组件必须包括信托法律条款第4.e节中所述的简化BSD许可证文本，并提供简化BSD许可证中所述的无担保。
Table of Contents
目录
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 4
2. Purpose and Scope . . . . . . . . . . . . . . . . . . . . . . 4
3. Terms and Definitions . . . . . . . . . . . . . . . . . . . . 4
3.1. Reference Path . . . . . . . . . . . . . . . . . . . . . 4
3.2. Subscriber . . . . . . . . . . . . . . . . . . . . . . . 5
3.3. Dedicated Component (Links or Nodes) . . . . . . . . . . 5
3.4. Shared Component (Links or Nodes) . . . . . . . . . . . . 5
3.5. Resource Transition Point . . . . . . . . . . . . . . . . 5
3.6. Service Demarcation Point . . . . . . . . . . . . . . . . 5
3.7. Managed and Unmanaged Sub-paths . . . . . . . . . . . . . 6
4. Reference Path . . . . . . . . . . . . . . . . . . . . . . . 6
5. Measurement Points . . . . . . . . . . . . . . . . . . . . . 7
6. Examples of Reference Paths with Various Technologies . . . . 11
7. Example of Reference Path with Resource Transition . . . . . 13
8. Security Considerations . . . . . . . . . . . . . . . . . . . 14
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 15
9.1. Normative References . . . . . . . . . . . . . . . . . . 15
9.2. Informative References . . . . . . . . . . . . . . . . . 16
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 4
2. Purpose and Scope . . . . . . . . . . . . . . . . . . . . . . 4
3. Terms and Definitions . . . . . . . . . . . . . . . . . . . . 4
3.1. Reference Path . . . . . . . . . . . . . . . . . . . . . 4
3.2. Subscriber . . . . . . . . . . . . . . . . . . . . . . . 5
3.3. Dedicated Component (Links or Nodes) . . . . . . . . . . 5
3.4. Shared Component (Links or Nodes) . . . . . . . . . . . . 5
3.5. Resource Transition Point . . . . . . . . . . . . . . . . 5
3.6. Service Demarcation Point . . . . . . . . . . . . . . . . 5
3.7. Managed and Unmanaged Sub-paths . . . . . . . . . . . . . 6
4. Reference Path . . . . . . . . . . . . . . . . . . . . . . . 6
5. Measurement Points . . . . . . . . . . . . . . . . . . . . . 7
6. Examples of Reference Paths with Various Technologies . . . . 11
7. Example of Reference Path with Resource Transition . . . . . 13
8. Security Considerations . . . . . . . . . . . . . . . . . . . 14
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 15
9.1. Normative References . . . . . . . . . . . . . . . . . . 15
9.2. Informative References . . . . . . . . . . . . . . . . . 16
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17
This document defines a reference path for Large-scale Measurement of Broadband Access Performance (LMAP) or similar measurement projects. The series of IP Performance Metrics (IPPM) RFCs have developed terms that are generally useful for path description (see Section 5 of [RFC2330]). There are a limited number of additional terms defined in this memo.
本文件定义了宽带接入性能（LMAP）大规模测量或类似测量项目的参考路径。一系列IP性能指标（IPPM）RFC制定了通常用于路径描述的术语（见[RFC2330]第5节）。本备忘录中定义的附加术语数量有限。
The reference path (see Section 3.1 and Figure 1 of [Y.1541], including the accompanying discussion) is usually needed when attempting to communicate precisely about the components that comprise the path, and is often expressed in terms of their number (hops) and geographic location. This memo takes the path definition further by establishing a set of measurement points along the path and ascribing a unique designation to each point. This topic has been previously developed in Section 5.1 of [RFC3432] and as part of the updated framework for composition and aggregation in Section 4 of [RFC5835]. Section 4.1 of [RFC5835] defines the term "measurement point".
参考路径（见[Y.1541]第3.1节和图1，包括附带的讨论）通常在试图准确传达构成该路径的组件时需要，并且通常以其数量（跳数）和地理位置表示。本备忘录通过沿路径建立一组测量点，并为每个点指定一个唯一的名称，进一步定义了路径。本主题先前已在[RFC3432]第5.1节中开发，并作为[RFC5835]第4节中更新的合成和聚合框架的一部分。[RFC5835]第4.1节定义了术语“测量点”。
Measurement points and the paths they inhabit are often described in general terms, like "end-to-end", "user-to-user", or "access". These terms alone are insufficient for the scientific method, since we need to clarify issues such as: What is an end? Where is a user located? Is the home network included?
测量点及其所在的路径通常用一般术语描述，如“端到端”、“用户到用户”或“访问”。这些术语本身不足以解释科学方法，因为我们需要澄清这样的问题：什么是目的？用户位于哪里？包括家庭网络吗？
As an illustrative example, consider a measurement agent in an LMAP system. When it reports its measurement results, rather than detailing its IP address and that of its measurement peer, it may prefer to describe the measured path segment abstractly (perhaps for privacy reasons), e.g., 'from a measurement agent at a home gateway to a measurement peer at a DSLAM.' This memo provides the definition for such abstract 'measurement points' and, therefore, the portion of 'reference path' between them.
作为一个说明性的例子，考虑LMAP系统中的测量代理。当其报告其测量结果时，与其详细说明其IP地址及其测量对等方的IP地址，不如抽象地描述测量路径段（可能出于隐私原因），例如。，“从家庭网关上的测量代理到DSLAM上的测量对等点。”本备忘录提供了此类抽象“测量点”的定义，以及它们之间的“参考路径”部分。
The motivation for this memo is to provide an unambiguous framework to describe measurement coverage or scope of the reference path. This is an essential part of the metadata to describe measurement results. Measurements conducted over different path scopes are not a valid basis for performance comparisons. We note that additional measurement context information may be necessary to support a valid comparison of results.
本备忘录的目的是提供一个明确的框架来描述参考路径的测量覆盖范围或范围。这是元数据中描述测量结果的重要部分。在不同路径范围内进行的测量不是性能比较的有效基础。我们注意到，可能需要额外的测量背景信息来支持结果的有效比较。
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119].
本文件中的关键词“必须”、“不得”、“要求”、“应”、“不应”、“应”、“不应”、“建议”、“可”和“可选”应按照RFC 2119[RFC2119]中所述进行解释。
The scope of this memo is to define a reference path for LMAP activities with a sufficient level of detail to determine the location of different measurement points along a path without ambiguity. These conventions are likely to be useful in other measurement projects and to describe the applicable measurement scope for some metrics.
本备忘录的范围是定义LMAP活动的参考路径，具有足够的详细程度，以确定路径上不同测量点的位置，而不会产生歧义。这些约定可能在其他度量项目中有用，并描述某些度量的适用度量范围。
The connection between the reference path and specific network technologies (with differing underlying architectures) is within the scope of this memo, and examples are provided. Both wired and wireless technologies are in scope.
参考路径和特定网络技术（具有不同的底层架构）之间的连接在本备忘录的范围内，并提供了示例。有线和无线技术都在范围之内。
The purpose is to create an efficient way to describe the location of the measurement point(s) used to conduct a particular measurement so that the measurement result will be adequately described in terms of scope or coverage. This should serve many measurement uses, including:
目的是创建一种有效的方法来描述用于进行特定测量的测量点的位置，以便在范围或覆盖范围方面充分描述测量结果。这应适用于多种测量用途，包括：
o diagnostic, where the same metric would be measured on different sub-paths bounded by measurement points (see Section 4.10 of [RFC5835]), for example, to isolate the sub-path contributing the majority of impairment levels observed on a path.
o 诊断，在由测量点（参见[RFC5835]第4.10节）限定的不同子路径上测量相同的度量，例如，隔离导致路径上观察到的大部分损伤水平的子路径。
o comparison, where the same metric may be measured on equivalent portions of different network infrastructures, for example, to compare the performance of wired and wireless home network technologies.
o 比较，其中可在不同网络基础设施的等效部分上测量相同度量，例如，以比较有线和无线家庭网络技术的性能。
This section defines key terms and concepts for this memo.
本节定义了本备忘录的关键术语和概念。
A reference path is a serial combination of hosts, routers, switches, links, radios, and processing elements that comprise all the network elements traversed by each packet in a flow between the source and destination hosts. A reference path also indicates the various boundaries present, such as administrative boundaries. A reference path is intended to be equally applicable to all IP and link-layer
参考路径是主机、路由器、交换机、链路、无线电和处理元件的串行组合，这些元件包括源主机和目的主机之间的流中每个分组所穿越的所有网络元件。参考路径还指示存在的各种边界，例如管理边界。参考路径旨在同等适用于所有IP和链路层
networking technologies. Therefore, the components are generically defined, but their functions should have a clear counterpart or be obviously omitted in any network architecture.
网络技术。因此，组件是通用定义的，但是它们的功能应该有一个明确的对应项，或者在任何网络体系结构中都可以明显省略。
A subscriber is an entity (associated with one or more users) that is engaged in a subscription with a service provider. The subscriber is allowed to subscribe and unsubscribe to services and to register a user or a list of users authorized to enjoy these services. [Q.1741]
订户是与服务提供商进行订阅的实体（与一个或多个用户关联）。订阅者可以订阅和取消订阅服务，并可以注册一个用户或一份授权享受这些服务的用户名单。[问题1741]
Both the subscriber and service provider are allowed to set the limits relative to the use that associated users make of subscribed services.
订阅者和服务提供者都可以设置与关联用户对订阅服务的使用相关的限制。
All resources of a dedicated component (typically a link or node on the reference path) are allocated to serving the traffic of an individual subscriber. Resources include transmission time-slots, queue space, processing for encapsulation and address/port translation, and others. A dedicated component can affect the performance of the reference path or the performance of any sub-path where the component is involved.
专用组件（通常是参考路径上的链路或节点）的所有资源被分配用于服务单个订户的通信量。资源包括传输时隙、队列空间、封装处理和地址/端口转换等。专用组件可能会影响参考路径的性能或涉及组件的任何子路径的性能。
A component on the reference path is designated a "shared component" when the traffic associated with multiple subscribers is served by common resources.
当与多个订阅者相关联的通信量由公共资源提供服务时，参考路径上的组件被指定为“共享组件”。
This is a point between dedicated and shared components on a reference path that may be a point of significance and is identified as a transition between two types of resources.
这是参考路径上专用组件和共享组件之间的一个点，可能是一个重要点，并被确定为两种资源类型之间的过渡。
This is the point where a service managed by the service provider begins (or ends) and varies by technology. For example, this point is usually defined as the Ethernet interface on a residential gateway or modem where the scope of a packet transfer service begins and ends. In the case of a WiFi service, this would be an air interface within the intended service boundary (e.g., walls of the coffee shop). The demarcation point may be within an integrated endpoint using an air interface (e.g., Long-Term Evolution User Equipment (LTE UE)). Ownership does not necessarily affect the demarcation point; a
这是由服务提供商管理的服务开始（或结束）的点，并因技术而异。例如，这一点通常定义为住宅网关或调制解调器上的以太网接口，其中数据包传输服务的范围开始和结束。对于WiFi服务，这将是预期服务边界内的空中接口（例如，咖啡馆的墙壁）。分界点可以位于使用空中接口（例如，长期演进用户设备（LTE-UE））的集成端点内。所有权不一定影响分界点；A.
subscriber may own all equipment on their premises, but it is likely that the service provider will certify such equipment for connection to their network or that a third-party will certify standards compliance.
订户可能拥有其经营场所内的所有设备，但服务提供商可能会证明此类设备连接到其网络，或者第三方将证明符合标准。
Service providers are responsible for the portion of the path they manage. However, most paths involve a sub-path that is beyond the management of the subscriber's service provider. This means that private networks, wireless networks using unlicensed frequencies, and the networks of other service providers are designated as unmanaged sub-paths. The service demarcation point always divides managed and unmanaged sub-paths.
服务提供商负责他们管理的路径部分。然而，大多数路径都涉及一个子路径，该子路径超出了订户的服务提供商的管理范围。这意味着专用网络、使用未授权频率的无线网络以及其他服务提供商的网络被指定为非托管子路径。服务分界点始终划分托管和非托管子路径。
This section defines a reference path for Internet communication.
本节定义了Internet通信的参考路径。
Subsc. -- Private -- Private -- Service-- Intra IP -- GRA -- Transit ...
device Net #1 Net #2 Demarc. Access GW GRA GW
Subsc. -- Private -- Private -- Service-- Intra IP -- GRA -- Transit ...
device Net #1 Net #2 Demarc. Access GW GRA GW
... Transit -- GRA -- Service -- Private -- Private -- Destination
GRA GW GW Demarc. Net #n Net #n+1 Host
... Transit -- GRA -- Service -- Private -- Private -- Destination
GRA GW GW Demarc. Net #n Net #n+1 Host
GRA = Globally Routable Address GW = Gateway
GRA=全局可路由地址GW=网关
Figure 1: Reference Path
图1：参考路径
The following are descriptions of reference path components that may not be clear from their name alone.
以下是引用路径组件的说明，这些组件可能仅从名称上看不清楚。
o Subsc. (Subscriber) device - This is a host that normally originates and terminates communications conducted over the IP packet transfer service.
o 潜艇。（订户）设备-这是一台主机，通常通过IP数据包传输服务发起和终止通信。
o Private Net #x - This is a network of devices owned and operated by the Internet service subscriber. In some configurations, one or more private networks and the device that provides the service demarcation point are collapsed in a single device (ownership may shift to the service provider); this should be noted as part of the path description.
o 专用网络#x-这是一个由互联网服务用户拥有和运营的设备组成的网络。在一些配置中，一个或多个专用网络和提供服务分界点的设备折叠在单个设备中（所有权可能转移到服务提供商）；这应作为路径描述的一部分加以说明。
o Intra IP Access - This is the first point in the access architecture, beyond the service demarcation, where a globally routable IP address is exposed and used for routing. In architectures that use tunneling, this point may be equivalent to the Globally Routable Address Gateway (GRA GW). This point could also collapse to the device providing the service demarcation, in principle. Only one Intra IP Access point is shown, but they can be identified in any access network.
o 内部IP访问-这是访问体系结构中的第一个点，超越了服务界限，其中公开了一个全局可路由的IP地址并用于路由。在使用隧道的体系结构中，这一点可能相当于全局可路由地址网关（GRA GW）。原则上，这一点也可能崩溃到提供服务划分的设备。只显示了一个IP内接入点，但可以在任何接入网络中识别它们。
o GRA GW - This is the point of interconnection between a service provider's administrative domain and the rest of the Internet, where routing will depend on the GRAs in the IP header.
o GRA GW-这是服务提供商的管理域和互联网其余部分之间的互连点，路由将取决于IP报头中的GRA。
o Transit GRA GW - If one or more networks intervene between the service provider's access networks of the subscriber and of the destination host, then such networks are designated "transit" and are bounded by two transit GRA GWs.
o Transit GRA GW-如果一个或多个网络介入用户和目标主机的服务提供商接入网络之间，则此类网络被指定为“Transit”，并由两个Transit GRA GWs限定。
Use of multiple IP address families in the measurement path must be noted, as the conversions between IPv4 and IPv6 certainly influence the visibility of a GRA for each family.
必须注意在测量路径中使用多个IP地址族，因为IPv4和IPv6之间的转换肯定会影响每个族GRA的可见性。
In the case that a private address space is used throughout an access architecture, then the Intra IP Access points must use the same address space as the service demarcation point, and the Intra IP Access points must be selected such that a test between these points produces a useful assessment of access performance (e.g., includes both shared and dedicated access link infrastructure).
在整个接入架构使用私有地址空间的情况下，IP内接入点必须使用与服务分界点相同的地址空间，并且必须选择IP内接入点，以便这些点之间的测试产生对接入性能的有用评估（例如，包括共享和专用访问链路基础设施）。
A key aspect of measurement points, beyond the definition in Section 4.1 of [RFC5835], is that the innermost IP header and higher-layer information must be accessible through some means. This is essential to measure IP metrics. There may be tunnels and/or other layers that encapsulate the innermost IP header, even adding another IP header of their own.
测量点的一个关键方面超出了[RFC5835]第4.1节中的定义，即必须通过某种方式访问最内层的IP头和更高层的信息。这对于衡量IP指标至关重要。可能有隧道和/或其他层封装最里面的IP头，甚至添加自己的另一个IP头。
In general, measurement points cannot always be located exactly where desired. However, the definition in [RFC5835] and the discussion in Section 5.1 of [RFC3432] indicate that allowances can be made; for example, it is nearly ideal when there are deterministic errors that can be quantified between desired and actual measurement points.
通常，测量点不能总是精确地定位在所需的位置。然而，[RFC5835]中的定义和[RFC3432]第5.1节中的讨论表明，可以进行津贴；例如，当期望测量点和实际测量点之间存在可量化的确定性误差时，这几乎是理想的。
The figure below illustrates the assignment of measurement points to selected components of the reference path.
下图说明了将测量点分配给参考路径的选定组件。
Subsc. -- Private -- Private -- Service-- Intra IP -- GRA -- Transit ...
device Net #1 Net #2 Demarc. Access GW GRA GW
mp000 mp100 mp150 mp190 mp200
Subsc. -- Private -- Private -- Service-- Intra IP -- GRA -- Transit ...
device Net #1 Net #2 Demarc. Access GW GRA GW
mp000 mp100 mp150 mp190 mp200
... Transit -- GRA -- Service -- Private -- Private -- Destination
GRA GW GW Demarc. Net #n Net #n+1 Host
mpX90 mp890 mp800 mp900
... Transit -- GRA -- Service -- Private -- Private -- Destination
GRA GW GW Demarc. Net #n Net #n+1 Host
mpX90 mp890 mp800 mp900
GRA = Globally Routable Address GW = Gateway
GRA=全局可路由地址GW=网关
Figure 2: Reference Path with Measurement Point Designations
图2：带有测量点名称的参考路径
Each measurement point on a specific reference path MUST be assigned a unique number. To facilitate interpretation of the results, the measuring organization (and whoever it shares results with) MUST have an unambiguous understanding of what path or point was measured. In order to achieve this, a set of numbering recommendations follow.
必须为特定参考路径上的每个测量点分配唯一编号。为了便于解释结果，测量组织（以及与之共享结果的人）必须明确了解测量的路径或点。为了实现这一点，以下是一组编号建议。
When communicating the results of measurements, the measuring organization SHOULD supply a diagram similar to Figure 2 (with the technology-specific information in examples that follow) and MUST supply it when additional measurement point numbers have been defined and used (with sufficient detail to identify measurement locations in the path).
在传达测量结果时，测量组织应提供类似于图2的图表（在下面的示例中包含特定于技术的信息），并且必须在定义和使用其他测量点编号时提供该图表（具有足够的细节以确定路径中的测量位置）。
Ideally, the consumer of measurement results would know the location of a measurement point on the reference path from the measurement point number alone; the recommendations below provide a way to accomplish this goal. Although the initial numbering may be fully compliant with this system, changing circumstances could, over time, lead to gaps in network numbers or non-monotonic measurement point number assignments along the path. Such circumstances could include growth, consolidation, re-arrangement, and change of ownership of the network. These are examples of reasonable causes for numbering deviations that must be identified on the reference path diagram, as required above.
理想情况下，测量结果的使用者将仅从测量点编号知道参考路径上测量点的位置；下面的建议提供了实现这一目标的方法。虽然初始编号可能完全符合该系统，但随着时间的推移，不断变化的情况可能会导致网络编号出现缺口或路径上非单调的测量点编号分配。这种情况可能包括网络的增长、整合、重组和所有权变更。这些是必须在参考路径图上识别的编号偏差的合理原因示例，如上所述。
While the numbering of a measurement point is in the context of a particular path, for simplicity, the measuring organization SHOULD use the same numbering for a device (playing the same role) on all the measurement paths through it. Similarly, whilst the measurement point numbering is in the context of a particular measuring organization, organizations with similar technologies and
当测量点的编号在特定路径的上下文中时，为简单起见，测量组织应在通过它的所有测量路径上对设备使用相同的编号（扮演相同的角色）。同样，虽然测量点编号是在特定测量组织的背景下进行的，但具有类似技术和经验的组织
architectures are encouraged to coordinate on local numbering and diagrams.
鼓励架构在本地编号和图表上进行协调。
The measurement point numbering system, mpXnn, has two independent parts:
测量点编号系统mpXnn有两个独立部分：
1. The X in mpXnn indicates the network number. The network with the subscriber's device is network 0. The network of a different organization (administrative or ownership domains) SHOULD be assigned a different number. Each successive network number SHOULD be one greater than the previous network's number. Two circumstances make it necessary to designate X=9 in the destination host's network and X=8 for the service provider network at the destination:
1. mpXnn中的X表示网络号。与订户设备的网络为网络0。不同组织（管理域或所有权域）的网络应分配不同的编号。每个连续的网络号应比前一个网络号大一个。有两种情况需要在目标主机的网络中指定X=9，在目标主机的服务提供商网络中指定X=8：
A. The number of transit networks is unknown.
A.公交网络的数量未知。
B. The number of transit networks varies over time.
B.公交网络的数量随时间而变化。
2. The nn in mpXnn indicates the measurement point and is locally assigned by network X. The following conventions are suggested:
2. mpXnn中的nn表示测量点，由网络X在本地分配。建议采用以下约定：
A. 00 SHOULD be used for a measurement point at the subscriber's device and at the service demarcation point or GW nearest to the subscriber's device for transit networks.
A.00应用于用户设备和服务分界点的测量点，或距离传输网络用户设备最近的GW。
B. 90 SHOULD be used for a measurement point at the GW of a network (opposite from the subscriber's device or service demarcation).
B.90应用于网络GW处的测量点（与用户设备或服务分界相反）。
C. In most networks, measurement point numbers SHOULD monotonically increase from the point nearest the subscriber's device to the opposite network boundary on the path (but see item D for an exception).
C.在大多数网络中，测量点编号应从距离用户设备最近的点到路径上的相对网络边界单调增加（但例外情况见D项）。
D. When a destination host is part of the path, 00 SHOULD be used for a measurement point at the destination host and at the destination's service demarcation point. Measurement point numbers SHOULD monotonically increase from the point nearest the destination's host to the opposite network boundary on the path ONLY in these networks. This directional numbering reversal allows consistent 00 designation for end hosts and service demarcation.
D.当目标主机是路径的一部分时，应将00用作目标主机和目标服务分界点处的测量点。仅在这些网络中，测量点编号应从距离目的地主机最近的点到路径上的相对网络边界单调增加。此方向编号反转允许终端主机和服务划分的一致00指定。
E. 50 MAY be used for an intermediate measurement point of significance, such as a Network Address Translator (NAT).
E.50可用于重要的中间测量点，例如网络地址转换器（NAT）。
F. 20 MAY be used for a traffic aggregation point, such as a Digital Subscriber Line Access Multiplexer (DSLAM) within a network.
F.20可用于业务聚合点，例如网络内的数字用户线接入多路复用器（DSLAM）。
G. Any other measurement points SHOULD be assigned unused integers between 01 and 99. The assignment SHOULD be stable for at least the duration of a particular measurement study and SHOULD avoid numbers that have been assigned to other locations within network X (unless the assignment is considered sufficiently stale). Subnetworks or domains within a network are useful locations for measurement points.
G.应为任何其他测量点分配01和99之间未使用的整数。分配应至少在特定测量研究期间保持稳定，并应避免分配给网络X内其他位置的数字（除非分配被认为足够陈旧）。网络中的子网或域是测量点的有用位置。
When supplying a diagram of the reference path and measurement points, the operator of the measurement system MUST indicate the reference path, the numbers (mpXnn) of the measurement points, and the technology-specific definition of any measurement point other than X00 and X90 with sufficient detail to clearly define its location (similar to the technology-specific examples in Section 6 of this document).
当提供参考路径和测量点的图表时，测量系统的操作员必须指示参考路径、测量点的编号（mpXnn）以及除X00和X90以外的任何测量点的技术特定定义，并提供足够的细节，以清楚地定义其位置（类似于本文件第6节中的技术特定示例）。
If the number of intermediate networks (between the source and destination) is not known or is unstable, then this SHOULD be indicated on the diagram, and results from measurement points within those networks need to be treated with caution.
如果中间网络（源和目标之间）的数量未知或不稳定，则应在图表上注明，并且需要谨慎处理这些网络内测量点的结果。
Notes:
笔记：
o The terminology "on-net" and "off-net" is sometimes used when referring to the subscriber's Internet Service Provider (ISP) measurement coverage. With respect to the reference path, tests between mp100 and mp190 are "on-net".
o 术语“网上”和“网外”有时用于指订户的互联网服务提供商（ISP）测量覆盖范围。关于参考路径，mp100和mp190之间的测试是“在线测试”。
o Widely deployed broadband Internet access measurements have used pass-through devices [SK] (at the subscriber's location) directly connected to the service demarcation point; this would be located at mp100.
o 广泛部署的宽带互联网接入测量使用直接连接到服务分界点的直通设备[SK]（在用户位置）；这将位于mp100。
o The networking technology must be indicated for the measurement points used, especially the interface standard and configured speed (because the measurement connectivity itself can be a limiting factor for the results).
o 必须为所使用的测量点指明网络技术，特别是接口标准和配置速度（因为测量连接性本身可能是结果的限制因素）。
o If it can be shown that a link connecting to a measurement point has reliably deterministic performance or negligible impairments, then the remote end of the connecting link is an equivalent point for some methods of measurement (although those methods should describe this possibility in detail, it is not in scope to provide such methods here). In any case, the presence of a link and claimed equivalent measurement point must be reported.
o 如果可以证明连接到测量点的链路具有可靠的确定性性能或可忽略的损伤，则连接链路的远端是某些测量方法的等效点（尽管这些方法应详细描述这种可能性，但此处不提供此类方法）。在任何情况下，必须报告链路的存在和声称的等效测量点。
o Some access network architectures may have an additional traffic aggregation device between mp100 and mp150. Use of a measurement point at this location would require a local number and diagram.
o 一些接入网络架构可能在mp100和mp150之间具有额外的流量聚合设备。在该位置使用测量点需要本地编号和图表。
o A Carrier Grade NAT (CGN) deployed in the service provider's access network would be positioned between mp100 and mp190, and the egress side of the CGN may be designated mp150. mp150 is generally an intermediate measurement point in the same address space as mp190.
o 部署在服务提供商的接入网络中的载波级NAT（CGN）将位于mp100和mp190之间，并且CGN的出口侧可以被指定为mp150。mp150通常是与mp190位于同一地址空间中的中间测量点。
o In the case that private address space is used in an access architecture, mp100 may need to use the same address space as its "on-net" measurement point counterpart so that a test between these points produces a useful assessment of network performance. Tests between mp000 and mp100 could use a different private address space, and when the globally routable side of a CGN is at mp150, the private address side of the CGN could be designated mp149 for tests with mp100.
o 在接入体系结构中使用专用地址空间的情况下，mp100可能需要使用与其“在线”测量点对应物相同的地址空间，以便这些点之间的测试产生对网络性能的有用评估。mp000和mp100之间的测试可以使用不同的专用地址空间，并且当CGN的全局可路由侧位于mp150时，CGN的专用地址侧可以指定为mp149，以便使用mp100进行测试。
o Measurement points at transit GRA GWs are numbered mpX00 and mpX90, where X is the lowest positive integer not already used in the path. The GW of the first transit network is shown with point mp200 and the last transit network GW with mpX90.
o transit GRA GWs处的测量点编号为mpX00和mpX90，其中X是路径中尚未使用的最小正整数。第一个公交网络的GW显示为点mp200，最后一个公交网络的GW显示为点mpX90。
This section and those that follow are intended to provide example mappings between particular network technologies and the reference path.
本节和后续章节旨在提供特定网络技术和参考路径之间的示例映射。
We provide an example for 3G cellular access below.
下面我们提供一个3G蜂窝接入的示例。
Subscriber -- Private --- Service ------------- GRA --- Transit ...
device Net #1 Demarc. GW GRA GW
mp000 mp100 mp190 mp200
Subscriber -- Private --- Service ------------- GRA --- Transit ...
device Net #1 Demarc. GW GRA GW
mp000 mp100 mp190 mp200
|_____________UE______________|___RAN+Core____|___GGSN__|
|_____Unmanaged sub-path_____|____Managed sub-path_____|
|_____________UE______________|___RAN+Core____|___GGSN__|
|_____Unmanaged sub-path_____|____Managed sub-path_____|
GRA = Globally Routable Address GW = Gateway UE = User Equipment RAN = Radio Access Network GGSN = Gateway General Packet Radio Service (GPRS) Support Node
GRA=全局可路由地址GW=网关UE=用户设备RAN=无线接入网络GGSN=网关通用分组无线业务（GPRS）支持节点
Figure 3: Example of Reference Path with 3G Cellular Access
图3:3G蜂窝接入的参考路径示例
Next, we provide an example of DSL access. Consider the case where:
接下来，我们提供一个DSL访问的示例。考虑以下情况：
o The Customer Premises Equipment (CPE) has a NAT device that is configured with a public IP address.
o 客户场所设备（CPE）具有配置有公共IP地址的NAT设备。
o The CPE consists of a wired residential GW and modem internally connected (via Private Net #2) to an embedded home router and WiFi access point (Private Net #1). All subscriber devices (UE) attach to the CPE through the WiFi access. mp100 is on the modem side of Private Net #2.
o CPE由有线住宅GW和调制解调器组成，内部连接（通过专用网2）至嵌入式家庭路由器和WiFi接入点（专用网1）。所有用户设备（UE）通过WiFi接入连接到CPE。mp100位于专用网络2的调制解调器端。
We believe this is a fairly common configuration in some parts of the world and is fairly simple as well.
我们认为这在世界上的某些地方是一种相当常见的配置，而且也相当简单。
This case would map into the defined reference measurement points as follows:
这种情况将映射到定义的参考测量点，如下所示：
Subsc. -- Private -- Private -- Service-- Intra IP -- GRA -- Transit ...
device Net #1 Net #2 Demarc. Access GW GRA GW
mp000 mp100 mp150 mp190 mp200
|--UE--|------------CPE/NAT--------|------|-BRAS-|------|
|------DSL Network---|
|________Unmanaged sub-path________|__Managed sub-path__|
Subsc. -- Private -- Private -- Service-- Intra IP -- GRA -- Transit ...
device Net #1 Net #2 Demarc. Access GW GRA GW
mp000 mp100 mp150 mp190 mp200
|--UE--|------------CPE/NAT--------|------|-BRAS-|------|
|------DSL Network---|
|________Unmanaged sub-path________|__Managed sub-path__|
GRA = Globally Routable Address GW = Gateway BRAS = Broadband Remote Access Server
GRA=全局可路由地址GW=网关BRAS=宽带远程访问服务器
Figure 4: Example of Reference Path with DSL Access
图4:DSL接入的参考路径示例
Consider another access network case where:
考虑另一个接入网络的情况：
o The CPE is a NAT device that is configured with a private IP address.
o CPE是配置有专用IP地址的NAT设备。
o There is a CGN located deep in the access ISP network.
o 在接入ISP网络的深处有一个CGN。
o The CPE is a home router that has also an incorporated a WiFi access point and this is the only networking device in the home network, all endpoints attach directly to the CPE through the WiFi access.
o CPE是一个家庭路由器，它还集成了一个WiFi接入点，这是家庭网络中唯一的网络设备，所有端点通过WiFi接入直接连接到CPE。
We believe this is becoming a fairly common configuration in some parts of the world.
我们认为，在世界某些地区，这正在成为一种相当普遍的配置。
This case would map into the defined reference measurement points as follows:
这种情况将映射到定义的参考测量点，如下所示：
Subsc. -- Private ------------- Service-- Intra IP -- GRA -- Transit ...
device Net #1 Demarc. Access GW GRA GW
mp000 mp100 mp150 mp190 mp200
|--UE--|------------CPE/NAT--------|------|-CGN-|------|
|--Access Network---|
|________Unmanaged sub-path________|_Managed sub-path__|
Subsc. -- Private ------------- Service-- Intra IP -- GRA -- Transit ...
device Net #1 Demarc. Access GW GRA GW
mp000 mp100 mp150 mp190 mp200
|--UE--|------------CPE/NAT--------|------|-CGN-|------|
|--Access Network---|
|________Unmanaged sub-path________|_Managed sub-path__|
GRA = Globally Routable Address GW = Gateway CGN = Carrier Grade NAT
GRA=全局可路由地址GW=网关CGN=载波级NAT
Figure 5: Example of Reference Path with CGN
图5：带有CGN的参考路径示例
This section gives an example of shared and dedicated portions with the reference path. This example shows two resource transition points.
本节给出了带有参考路径的共享和专用部分的示例。此示例显示了两个资源转换点。
Consider the case where:
考虑以下情况：
o The CPE consists of a wired residential GW and modem (Private Net #2) connected to a WiFi access point (Private Net #1). The subscriber device (UE) attaches to the CPE through the WiFi access.
o CPE包括一个有线住宅GW和一个连接到WiFi接入点（专用网1）的调制解调器（专用网2）。用户设备（UE）通过WiFi接入连接到CPE。
o The WiFi subnetwork (Private Net #1) shares unlicensed radio channel resources with other WiFi access networks (and potentially other sources of interference); thus, this is a shared portion of the path.
o WiFi子网（专用网#1）与其他WiFi接入网络（以及潜在的其他干扰源）共享未经许可的无线信道资源；因此，这是路径的共享部分。
o The wired subnetwork (Private Net #2) and a portion of the service provider's network are dedicated resources (for a single subscriber); thus, there is a resource transition point between Private Net #1 and Private Net #2.
o 有线子网（专用网#2）和服务提供商网络的一部分是专用资源（针对单个用户）；因此，在专用网1和专用网2之间存在一个资源转换点。
o Subscriber traffic shares common resources with other subscribers upon reaching the CGN; thus, there is a resource transition point and further network components are designated as shared resources.
o 用户流量到达CGN后与其他用户共享公共资源；因此，存在资源转换点，并且进一步的网络组件被指定为共享资源。
We believe this is a fairly common configuration in parts of the world.
我们认为，这是世界部分地区相当普遍的配置。
This case would map into the defined reference measurement points as follows:
这种情况将映射到定义的参考测量点，如下所示：
Subsc. -- Private -- Private -- Access -- Intra IP -- GRA -- Transit ...
device Net #1 Net #2 Demarc. Access GW GRA GW
mp000 mp100 mp150 mp190 mp200
|--UE--|------------CPE/NAT--------|------|-CGN-|------|
| WiFi | 1000Base-T |--Access Network---|
Subsc. -- Private -- Private -- Access -- Intra IP -- GRA -- Transit ...
device Net #1 Net #2 Demarc. Access GW GRA GW
mp000 mp100 mp150 mp190 mp200
|--UE--|------------CPE/NAT--------|------|-CGN-|------|
| WiFi | 1000Base-T |--Access Network---|
|-Shared--|RT|------Dedicated------| RT |-----Shared------...
|_______Unmanaged sub-path________|_Managed sub-path__|
|-Shared--|RT|------Dedicated------| RT |-----Shared------...
|_______Unmanaged sub-path________|_Managed sub-path__|
GRA = Globally Routable Address GW = Gateway RT = Resource Transition Point
GRA=全局可路由地址GW=网关RT=资源转换点
Figure 6: Example of Reference Path with Two Reference Transition Points
图6：具有两个参考转换点的参考路径示例
Specification of a reference path and identification of measurement points on the path represent agreements among interested parties. They present no threat to the implementors of this memo, or to the Internet resulting from implementation of the guidelines provided here.
参考路径的规范和路径上测量点的标识表示相关方之间的协议。它们不会对本备忘录的实施者构成威胁，也不会因实施此处提供的指南而对互联网构成威胁。
Attacks at end hosts or identified measurement points are possible. However, there is no requirement to include IP addresses of hosts or other network devices in a reference path with measurement points that is compliant with this memo. As a result, the path diagrams with measurement point designation numbers do not aid such attacks.
可能在终端主机或已识别的测量点进行攻击。但是，不要求在参考路径中包含符合本备忘录要求的测量点的主机或其他网络设备的IP地址。因此，带有测量点指定编号的路径图不支持此类攻击。
Most network operators' diagrams of reference paths will bear a close resemblance to similar diagrams in relevant standards or other publicly available documents. However, when an operator must include
大多数网络运营商的参考路径图与相关标准或其他公开文件中的类似图非常相似。但是，当操作员必须包括
atypical network details in their diagram, e.g., to explain why a longer latency measurement is expected, then the diagram reveals some topological details and should be marked as confidential and shared with others under a specific agreement.
图中的非典型网络详细信息，例如，为了解释为什么预期延迟测量更长，图中显示了一些拓扑详细信息，应标记为机密，并根据特定协议与其他人共享。
When considering privacy of those involved in measurement or those whose traffic is measured, there may be sensitive information communicated to recipients of the network diagrams illustrating paths and measurement points described above. We refer the reader to the privacy considerations described in the Large Scale Measurement of Broadband Performance (LMAP) Framework [LMAP-FRAMEWORK], which covers active and passive measurement techniques and supporting material on measurement context. For example, the value of sensitive information can be further diluted by summarizing measurement results over many individuals or areas served by the provider. There is an opportunity enabled by forming anonymity sets described in [RFC6973] based on the reference path and measurement points in this memo. For example, all measurements from the subscriber device can be identified as "mp000", instead of using the IP address or other device information. The same anonymization applies to the Internet service provider, where their Internet gateway would be referred to as "mp190".
当考虑参与测量的人或其流量被测量的人的隐私时，可能存在传达给说明上述路径和测量点的网络图的接收者的敏感信息。我们建议读者参考大规模宽带性能测量（LMAP）框架[LMAP-Framework]中描述的隐私注意事项，该框架涵盖主动和被动测量技术以及测量上下文的支持材料。例如，敏感信息的价值可以通过汇总供应商服务的许多个人或区域的测量结果来进一步稀释。根据本备忘录中的参考路径和测量点，通过形成[RFC6973]中所述的匿名集，可以实现一个机会。例如，来自订户设备的所有测量值都可以标识为“mp000”，而不是使用IP地址或其他设备信息。同样的匿名也适用于互联网服务提供商，他们的互联网网关将被称为“mp190”。
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997, <http://www.rfc-editor.org/info/rfc2119>.
[RFC2119]Bradner，S.，“RFC中用于表示需求水平的关键词”，BCP 14，RFC 2119，1997年3月<http://www.rfc-editor.org/info/rfc2119>.
[RFC2330] Paxson, V., Almes, G., Mahdavi, J., and M. Mathis, "Framework for IP Performance Metrics", RFC 2330, May 1998, <http://www.rfc-editor.org/info/rfc2330>.
[RFC2330]Paxson，V.，Almes，G.，Mahdavi，J.，和M.Mathis，“IP性能度量框架”，RFC 2330，1998年5月<http://www.rfc-editor.org/info/rfc2330>.
[RFC3432] Raisanen, V., Grotefeld, G., and A. Morton, "Network performance measurement with periodic streams", RFC 3432, November 2002, <http://www.rfc-editor.org/info/rfc3432>.
[RFC3432]Raisanen，V.，Grotefeld，G.，和A.Morton，“周期流的网络性能测量”，RFC 3432，2002年11月<http://www.rfc-editor.org/info/rfc3432>.
[RFC5835] Morton, A. and S. Van den Berghe, "Framework for Metric Composition", RFC 5835, April 2010, <http://www.rfc-editor.org/info/rfc5835>.
[RFC5835]Morton，A.和S.Van den Berghe，“公制组合框架”，RFC 58352010年4月<http://www.rfc-editor.org/info/rfc5835>.
[LMAP-FRAMEWORK] Eardley, P., Morton, A., Bagnulo, M., Burbridge, T., Aitken, P., and A. Akhter, "A framework for large-scale measurement platforms (LMAP)", Work in Progress, draft-ietf-lmap-framework-10, January 2015.
[LMAP-FRAMEWORK]Eardley，P.，Morton，A.，Bagnulo，M.，Burbridge，T.，Aitken，P.，和A.Akhter，“大型测量平台框架（LMAP）”，正在进行的工作，草案-ietf-LMAP-FRAMEWORK-10，2015年1月。
[Q.1741] International Telecommunications Union, "IMT-2000 references to Release 9 of GSM-evolved UMTS core network", ITU-T Recommendation Q.1741.7, November 2011, <http://www.itu.int/rec/T-REC-Q.1741.7/en>.
[Q.1741]国际电信联盟，“IMT-2000参考GSM演进UMTS核心网络第9版”，ITU-T建议Q.1741.7，2011年11月<http://www.itu.int/rec/T-REC-Q.1741.7/en>.
[RFC6973] Cooper, A., Tschofenig, H., Aboba, B., Peterson, J., Morris, J., Hansen, M., and R. Smith, "Privacy Considerations for Internet Protocols", RFC 6973, July 2013, <http://www.rfc-editor.org/info/rfc6973>.
[RFC6973]Cooper，A.，Tschofenig，H.，Aboba，B.，Peterson，J.，Morris，J.，Hansen，M.，和R.Smith，“互联网协议的隐私考虑”，RFC 69732013年7月<http://www.rfc-editor.org/info/rfc6973>.
[SK] Crawford, S., "Test Methodology White Paper", SamKnows Whitebox Briefing Note , July 2011, <http://www.samknows.com/broadband/index.php>.
[SK]Crawford，S.，“测试方法白皮书”，SamKnows Whitebox简报，2011年7月<http://www.samknows.com/broadband/index.php>.
[Y.1541] International Telecommunications Union, "Network performance objectives for IP-based services", ITU-T Recommendation Y.1541, November 2011, <http://www.itu.int/rec/T-REC-Y.1541/en>.
[Y.1541]国际电信联盟，“基于IP的服务的网络性能目标”，ITU-T建议Y.1541，2011年11月<http://www.itu.int/rec/T-REC-Y.1541/en>.
Acknowledgments
致谢
Thanks to Matt Mathis, Charles Cook, Dan Romascanu, Lingli Deng, and Spencer Dawkins for review and comments.
感谢Matt Mathis、Charles Cook、Dan Romascanu、Lingli Deng和Spencer Dawkins的评论和评论。
Authors' Addresses
作者地址
Marcelo Bagnulo Universidad Carlos III de Madrid Av. Universidad 30 Leganes, Madrid 28911 Spain
马德里卡洛斯三世大学。西班牙马德里勒加内斯30大学28911
Phone: 34 91 6249500
EMail: marcelo@it.uc3m.es
URI: http://www.it.uc3m.es
Phone: 34 91 6249500
EMail: marcelo@it.uc3m.es
URI: http://www.it.uc3m.es
Trevor Burbridge BT Adastral Park, Martlesham Heath Ipswich United Kingdom
Trevor Burbridge BT Adastral公园，英国马特勒沙姆希思伊普斯维奇
EMail: trevor.burbridge@bt.com
EMail: trevor.burbridge@bt.com
Sam Crawford SamKnows
山姆·克劳福德知道
EMail: sam@samknows.com
EMail: sam@samknows.com
Philip Eardley BT Adastral Park, Martlesham Heath Ipswich United Kingdom
Philip Eardley BT Adastral公园，英国马特勒沙姆希思伊普斯维奇
EMail: philip.eardley@bt.com
EMail: philip.eardley@bt.com
Al Morton AT&T Labs 200 Laurel Avenue South Middletown, NJ United States
美国新泽西州劳雷尔大道南米德尔顿200号艾尔莫顿AT&T实验室
EMail: acmorton@att.com
EMail: acmorton@att.com